Mechatronic hybrid transmissions having two planetary gear sets and three motor/generators

ABSTRACT

An electrically variable transmission family providing low-content, low-cost electrically variable transmission mechanisms including first and second differential gear sets, a battery and three electric machines serving interchangeably as motors or generators. The three motor/generators are operable in a coordinated fashion to yield an EVT with a continuously variable range of speeds (including reverse).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/728,895 filed on Oct. 21, 2005, and which is hereby incorporatedby reference in its entirety.

TECHNICAL FIELD

The present invention relates to electrically variable transmissionshaving two planetary gear sets and three motor/generators that arecontrollable to provide continuously variable speed ratio ranges.

BACKGROUND OF THE INVENTION

Electric hybrid vehicles offer the potential for significant fueleconomy improvements over their conventional counterparts; however,their overall efficiency is limited by parasitic losses. In single-modeelectric variable transmissions (EVT) these losses are mostly attributedto electric machines rotating at high speeds. Two-mode EVTs offer theadvantage of reduced motor-generator speeds, but often suffer lossesattributed to high-pressure hydraulic pump and clutches needed for modeswitching. Significant vehicle fuel economy gains can be realized if thelosses associated with high-pressure hydraulic pump, clutches and highmotor-generator speeds are substantially eliminated.

SUMMARY OF THE INVENTION

This invention describes continuously-variable mechatronic hybridtransmissions that offer the advantages of multi-mode EVTs without theneed for clutches and the associated high pressure hydraulic pump.

The electrically variable transmission family of the present inventionprovides low-content, low-cost electrically variable transmissionmechanisms including first and second differential gear sets, a battery(or similar energy storage device) and three electric machines servinginterchangeably as motors or generators. Preferably, the differentialgear sets are planetary gear sets, but other gear arrangements may beimplemented, such as bevel gears or differential gearing to an offsetaxis.

In this description, the first and second planetary gear sets may becounted first to second in any order (i.e., left to right, right toleft).

Each of the two planetary gear sets has three members. The first, secondor third member of each planetary gear set can be any one of a sun gear,ring gear or carrier, or alternatively a pinion.

Each carrier can be either a single-pinion carrier (simple) or adouble-pinion carrier (compound).

The input shaft is continuously connected with a member of the planetarygear sets. The output shaft is continuously connected with anothermember of the planetary gear sets.

An interconnecting member continuously connects the first member of thefirst planetary gear set with the first member of the second planetarygear set.

A first motor/generator is connected to a member of the first planetarygear set.

A second motor/generator is connected to a member of the secondplanetary gear set.

A third motor/generator is connected to a member of the first or secondplanetary gear set.

In essence, the planetary gear arrangement has five nodes which areconnected with the input shaft, output shaft and three motor/generators.The electric motor/generators are connected with drive units, controlsystem and energy storage devices, such as a battery.

The three motor/generators are operated in a coordinated fashion toyield continuously variable forward and reverse speed ratios between theinput shaft and the output shaft, while minimizing the rotational speedsof the motor-generators and optimizing the overall efficiency of thesystem. The tooth ratios of the planetary gear sets can be suitablyselected to match specific applications.

The above features and advantages and other features and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a powertrain of a firstembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 2 is a schematic representation of a powertrain of a secondembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 3 is a schematic representation of a powertrain of a thirdembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 4 is a schematic representation of a powertrain of a fourthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 5 is a schematic representation of a powertrain of a fifthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 6 is a schematic representation of a powertrain of a sixthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 7 is a schematic representation of a powertrain of a seventhembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 8 is a schematic representation of a powertrain of an eighthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 9 is a schematic representation of a powertrain of a ninthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 10 is a schematic representation of a powertrain of a tenthembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 11 is a schematic representation of a powertrain of an eleventhembodiment including an electrically variable transmission incorporatinga family member of the present invention;

FIG. 12 is a schematic representation of a powertrain of a twelfthembodiment including an electrically variable transmission incorporatinga family member of the present invention; and

FIG. 13 is a schematic representation of a powertrain of a thirteenthembodiment including an electrically variable transmission incorporatinga family member of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1, a powertrain 10 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 14.Transmission 14 is designed to receive at least a portion of its drivingpower from the engine 12. As shown, the engine 12 has an output shaftthat serves as the input member 17 of the transmission 14. A transienttorque damper (not shown) may also be implemented between the engine 12and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 14.

An output member 19 of the transmission 14 is connected to a final drive16.

The transmission 14 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 20 and 30. The planetary gear set 20employs an outer gear member 24, typically designated as the ring gear.The ring gear member 24 circumscribes an inner gear member 22, typicallydesignated as the sun gear. A carrier member 26 rotatably supports aplurality of planet gears 27 such that each planet gear 27simultaneously, and meshingly engages both the outer, ring gear member24 and the inner, sun gear member 22 of the first planetary gear set 20.

The planetary gear set 30 also employs an outer gear member 34,typically designated as the ring gear. The ring gear member 34circumscribes an inner gear member 32, typically designated as the sungear. A carrier member 36 rotatably supports a plurality of planet gears37 such that each planet gear 37 simultaneously, and meshingly engagesboth the outer, ring gear member 34 and the inner, sun gear member 32 ofthe planetary gear set 30.

The input shaft 17 is continuously connected to the carrier member 36 ofthe planetary gear set 30. The output shaft 19 is continuously connectedto the ring gear member 34 of the planetary gear set 30.

An interconnecting member 70 continuously connects the ring gear member24 of the planetary gear set 20 with the ring gear member 34 of theplanetary gear set 30.

The first preferred embodiment 10 also incorporates first, second andthird motor/generators 80, 82 and 84, respectively. The stator of thefirst motor/generator 80 is secured to the transmission housing 60. Therotor of the first motor/generator 80 is secured to the sun gear member32 of the planetary gear set 30.

The stator of the second motor/generator 82 is secured to thetransmission housing 60. The rotor of the second motor/generator 82 issecured to the sun gear member 22 of the planetary gear set 20.

The stator of the third motor/generator 84 is secured to thetransmission housing 60. The rotor of the third motor/generator 84 issecured to the carrier member 26 of the planetary gear set 20.

Returning now to the description of the power sources, it should beapparent from the foregoing description, and with particular referenceto FIG. 1, that the transmission 14 selectively receives power from theengine 12. The hybrid transmission also receives power from an electricpower source 86, which is operably connected to a controller 88. Theelectric power source 86 may be one or more batteries. Other electricpower sources, such as capacitors or fuel cells, that have the abilityto provide, or store, and dispense electric power may be used in placeof or in combination with batteries without altering the concepts of thepresent invention. The speed ratio between the input shaft and outputshaft is prescribed by the speeds of the three motor/generators and thering gear/sun gear tooth ratios of the planetary gear sets. Those withordinary skill in the transmission art will recognize that desiredinput/output speed ratios can be realized by suitable selection of thespeeds of the three motor/generators.

Description of a Second Exemplary Embodiment

With reference to FIG. 2, a powertrain 110 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 114.Transmission 114 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 114. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 114.

An output member 19 of the transmission 114 is connected to a finaldrive 16.

The transmission 114 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 120 and 130. The planetary gear set120 employs an outer gear member 124, typically designated as the ringgear. The ring gear member 124 circumscribes an inner gear member 122,typically designated as the sun gear. A carrier member 126 rotatablysupports a plurality of planet gears 127 such that each planet gear 127simultaneously, and meshingly engages both the outer, ring gear member124 and the inner, sun gear member 122 of the first planetary gear set120.

The planetary gear set 130 also employs an outer gear member 134,typically designated as the ring gear. The ring gear member 134circumscribes an inner gear member 132, typically designated as the sungear. A carrier member 136 rotatably supports a plurality of planetgears 137 such that each planet gear 137 simultaneously, and meshinglyengages both the outer, ring gear member 134 and the inner, sun gearmember 132 of the planetary gear set 130.

The input shaft 17 is continuously connected to the carrier member 136of the planetary gear set 130. The output shaft 19 is continuouslyconnected to the ring gear member 134 of the planetary gear set 130.

An interconnecting member 170 continuously connects the ring gear member124 of the planetary gear set 120 with the carrier member 136 of theplanetary gear set 130.

The second preferred embodiment 110 also incorporates first, second andthird motor/generators 180, 182 and 184, respectively. The stator of thefirst motor/generator 180 is secured to the transmission housing 160.The rotor of the first motor/generator 180 is secured to the sun gearmember 132 of the planetary gear set 130.

The stator of the second motor/generator 182 is secured to thetransmission housing 160. The rotor of the second motor/generator 182 issecured to the sun gear member 122 of the planetary gear set 120.

The stator of the third motor/generator 184 is secured to thetransmission housing 160. The rotor of the third motor/generator 184 issecured to the carrier member 126 of the planetary gear set 120.

The hybrid transmission 114 receives power from the engine 12, and alsoexchanges power with an electric power source 186, which is operablyconnected to a controller 188.

Description of a Third Exemplary Embodiment

With reference to FIG. 3, a powertrain 210 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 214.Transmission 214 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 214. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 214.

An output member 19 of the transmission 214 is connected to a finaldrive 16.

The transmission 214 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 220 and 230. The planetary gear set220 employs an outer gear member 224, typically designated as the ringgear. The ring gear member 224 circumscribes an inner gear member 222,typically designated as the sun gear. A carrier member 226 rotatablysupports a plurality of planet gears 227 such that each planet gear 227simultaneously, and meshingly engages both the outer, ring gear member224 and the inner, sun gear member 222 of the first planetary gear set220.

The planetary gear set 230 also employs an outer gear member 234,typically designated as the ring gear. The ring gear member 234circumscribes an inner gear member 232, typically designated as the sungear. A carrier member 236 rotatably supports a plurality of planetgears 237 such that each planet gear 237 simultaneously, and meshinglyengages both the outer, ring gear member 234 and the inner, sun gearmember 232 of the planetary gear set 230.

The input shaft 17 is continuously connected to the carrier member 236of the planetary gear set 230. The output shaft 19 is continuouslyconnected to the ring gear member 234 of the planetary gear set 230.

An interconnecting member 270 continuously connects the carrier member226 with the carrier member 236.

The preferred embodiment 210 also incorporates first, second and thirdmotor/generators 280, 282 and 284, respectively. The stator of the firstmotor/generator 280 is secured to the transmission housing 260. Therotor of the first motor/generator 280 is secured to the sun gear member232 of the planetary gear set 230.

The stator of the second motor/generator 282 is secured to thetransmission housing 260. The rotor of the second motor/generator 282 issecured to the sun gear member 222 of the planetary gear set 220.

The stator of the third motor/generator 284 is secured to thetransmission housing 260. The rotor of the third motor/generator 284 issecured to the ring gear member 224 of the planetary gear set 220.

The hybrid transmission 214 receives power from the engine 12, and alsoexchanges power with an electric power source 286, which is operablyconnected to a controller 288.

Description of a Fourth Exemplary Embodiment

With reference to FIG. 4, a powertrain 310 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 314.Transmission 314 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 314. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 14. Anoutput member 19 of the transmission 314 is connected to a final drive16.

The transmission 314 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 320 and 330. The planetary gear set320 employs an outer gear member 324, typically designated as the ringgear. The ring gear member 324 circumscribes an inner gear member 322,typically designated as the sun gear. A carrier member 326 rotatablysupports a plurality of planet gears 327 such that each planet gear 327simultaneously, and meshingly engages both the outer, ring gear member324 and the inner, sun gear member 322 of the first planetary gear set320.

The planetary gear set 330 also employs an outer gear member 334,typically designated as the ring gear. The ring gear member 334circumscribes an inner gear member 332, typically designated as the sungear. A carrier member 336 rotatably supports a plurality of planetgears 337 such that each planet gear 337 simultaneously, and meshinglyengages both the outer, ring gear member 334 and the inner, sun gearmember 332 of the planetary gear set 330.

The input shaft 17 is continuously connected to the carrier member 326of the planetary gear set 320. The output shaft 19 is continuouslyconnected to the carrier member 336 of the planetary gear set 330.

An interconnecting member 370 continuously connects the ring gear member324 with the sun gear member 332.

The preferred embodiment 310 also incorporates first, second and thirdmotor/generators 380, 382 and 384, respectively. The stator of the firstmotor/generator 380 is secured to the transmission housing 360. Therotor of the first motor/generator 380 is secured to the sun gear member322.

The stator of the second motor/generator 382 is secured to thetransmission housing 360. The rotor of the second motor/generator 382 issecured to the ring gear member 324.

The stator of the third motor/generator 384 is secured to thetransmission housing 360. The rotor of the third motor/generator 384 issecured to the ring gear member 334.

The hybrid transmission 314 receives power from the engine 12, and alsoexchanges power with an electric power source 386, which is operablyconnected to a controller 388.

Description of a Fifth Exemplary Embodiment

With reference to FIG. 5, a powertrain 410 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 414.Transmission 414 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 414. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 414.An output member 19 of the transmission 414 is connected to a finaldrive 16.

The transmission 414 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 420 and 430. The planetary gear set420 employs an outer gear member 424, typically designated as the ringgear. The ring gear member 424 circumscribes an inner gear member 422,typically designated as the sun gear. A carrier member 426 rotatablysupports a plurality of planet gears 427 such that each planet gear 427simultaneously, and meshingly engages both the outer, ring gear member424 and the inner, sun gear member 422 of the first planetary gear set420.

The planetary gear set 430 also employs an outer gear member 434,typically designated as the ring gear. The ring gear member 434circumscribes an inner gear member 432, typically designated as the sungear. A carrier member 436 rotatably supports a plurality of planetgears 437 such that each planet gear 437 simultaneously, and meshinglyengages both the outer, ring gear member 434 and the inner, sun gearmember 432 of the planetary gear set 430.

The input shaft 17 is continuously connected to the ring gear member434. The output shaft 19 is continuously connected to the carrier member436.

An interconnecting member 470 continuously connects the carrier member426 with the carrier member 436.

The preferred embodiment 410 also incorporates first, second and thirdmotor/generators 480, 482 and 484, respectively. The stator of the firstmotor/generator 480 is secured to the transmission housing 460. Therotor of the first motor/generator 480 is secured to the sun gear member432.

The stator of the second motor/generator 482 is secured to thetransmission housing 460. The rotor of the second motor/generator 482 issecured to the sun gear member 422.

The stator of the third motor/generator 484 is secured to thetransmission housing 460. The rotor of the third motor/generator 484 issecured to the ring gear member 424.

The hybrid transmission 414 receives power from the engine 12, and alsoexchanges power with an electric power source 486, which is operablyconnected to a controller 488.

Description of a Sixth Exemplary Embodiment

With reference to FIG. 6, a powertrain 510 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 514.Transmission 514 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 514. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 514.An output member 19 of the transmission 514 is connected to a finaldrive 16.

The transmission 514 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 520 and 530. The planetary gear set520 employs an outer gear member 524, typically designated as the ringgear. The ring gear member 524 circumscribes an inner gear member 522,typically designated as the sun gear. A carrier member 526 rotatablysupports a plurality of planet gears 527 such that each planet gear 527simultaneously, and meshingly engages both the outer, ring gear member524 and the inner, sun gear member 522 of the planetary gear set 520.

The planetary gear set 530 also employs an outer gear member 534,typically designated as the ring gear. The ring gear member 534circumscribes an inner gear member 532, typically designated as the sungear. A carrier member 536 rotatably supports a plurality of planetgears 537 such that each planet gear 537 simultaneously, and meshinglyengages both the outer, ring gear member 534 and the inner, sun gearmember 532 of the planetary gear set 530.

The input shaft 17 is continuously connected to the carrier member 536.The output shaft 19 is continuously connected to the carrier member 526.

An interconnecting member 570 continuously connects the carrier member526 with the ring gear member 534.

The preferred embodiment 510 also incorporates first, second and thirdmotor/generators 580, 582 and 584, respectively. The stator of the firstmotor/generator 580 is secured to the transmission housing 560. Therotor of the first motor/generator 580 is secured to the sun gear member522.

The stator of the second motor/generator 582 is secured to thetransmission housing 560. The rotor of the second motor/generator 582 issecured to the ring gear member 524.

The stator of the third motor/generator 584 is secured to thetransmission housing 560. The rotor of the third motor/generator 584 issecured to the sun gear member 532.

The hybrid transmission 514 receives power from the engine 12, and alsoexchanges power with an electric power source 586, which is operablyconnected to a controller 588.

Description of a Seventh Exemplary Embodiment

With reference to FIG. 7, a powertrain 610 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 614.Transmission 614 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 614. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 614.An output member 19 of the transmission 614 is connected to a finaldrive 16.

The transmission 614 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 620 and 630. The planetary gear set620 employs an outer gear member 624, typically designated as the ringgear. The ring gear member 624 circumscribes an inner gear member 622,typically designated as the sun gear. A carrier member 626 rotatablysupports a plurality of planet gears 627 such that each planet gear 627simultaneously, and meshingly engages both the outer, ring gear member624 and the inner, sun gear member 622 of the first planetary gear set620.

The planetary gear set 630 also employs an outer gear member 634,typically designated as the ring gear. The ring gear member 634circumscribes an inner gear member 632, typically designated as the sungear. A carrier member 636 rotatably supports a plurality of planetgears 637 such that each planet gear 637 simultaneously, and meshinglyengages both the outer, ring gear member 634 and the inner, sun gearmember 632 of the planetary gear set 630.

The input shaft 17 is continuously connected to the carrier member 626.The output shaft 19 is continuously connected to the carrier member 636.

An interconnecting member 670 continuously connects the sun gear member622 with the carrier member 636.

The preferred embodiment 610 also incorporates first, second and thirdmotor/generators 680, 682 and 684, respectively. The stator of the firstmotor/generator 680 is secured to the transmission housing 660. Therotor of the first motor/generator 680 is secured to the ring gearmember 624.

The stator of the second motor/generator 682 is secured to thetransmission housing 660. The rotor of the second motor/generator 682 issecured to the sun gear member 632.

The stator of the third motor/generator 684 is secured to thetransmission housing 660. The rotor of the third motor/generator 684 issecured to the ring gear member 634.

The hybrid transmission 614 receives power from the engine 12, and alsoexchanges power with an electric power source 686, which is operablyconnected to a controller 688.

Description of an Eighth Exemplary Embodiment

With reference to FIG. 8, a powertrain 710 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 714.Transmission 714 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 714. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 714.An output member 19 of the transmission 714 is connected to a finaldrive 16.

The transmission 714 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 720 and 730. The planetary gear set720 employs an outer gear member 724, typically designated as the ringgear. The ring gear member 724 circumscribes an inner gear member 722,typically designated as the sun gear. A carrier member 726 rotatablysupports a plurality of planet gears 727 such that each planet gear 727simultaneously, and meshingly engages both the outer, ring gear member724 and the inner, sun gear member 722 of the planetary gear set 720.

The planetary gear set 730 also employs an outer gear member 734,typically designated as the ring gear. The ring gear member 734circumscribes an inner gear member 732, typically designated as the sungear. A carrier member 736 rotatably supports a plurality of planetgears 737 such that each planet gear 737 simultaneously, and meshinglyengages both the outer, ring gear member 734 and the inner, sun gearmember 732 of the planetary gear set 730.

The input shaft 17 is continuously connected to the carrier member 726.The output shaft 19 is continuously connected to the carrier member 736.

An interconnecting member 770 continuously connects the sun gear member722 with the sun gear member 732.

The preferred embodiment 710 also incorporates first, second and thirdmotor/generators 780, 782 and 784, respectively. The stator of the firstmotor/generator 780 is secured to the transmission housing 760. Therotor of the first motor/generator 780 is secured to the ring gearmember 724.

The stator of the second motor/generator 782 is secured to thetransmission housing 760. The rotor of the second motor/generator 782 issecured to the carrier member 736, and therefore the output member 19.

The stator of the third motor/generator 784 is secured to thetransmission housing 760. The rotor of the third motor/generator 784 issecured to the ring gear member 734.

The hybrid transmission 714 receives power from the engine 12, and alsoexchanges power with an electric power source 786, which is operablyconnected to a controller 788.

Description of a Ninth Exemplary Embodiment

With reference to FIG. 9, a powertrain 810 is shown, including an engine12 connected to one preferred embodiment of the improved electricallyvariable transmission (EVT), designated generally by the numeral 814.Transmission 814 is designed to receive at least a portion of itsdriving power from the engine 12. As shown, the engine 12 has an outputshaft that serves as the input member 17 of the transmission 814. Atransient torque damper (not shown) may also be implemented between theengine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 814.An output member 19 of the transmission 814 is connected to a finaldrive 16.

The transmission 814 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 820 and 830. The planetary gear set820 employs an outer gear member 824, typically designated as the ringgear. The ring gear member 824 circumscribes an inner gear member 822,typically designated as the sun gear. A carrier member 826 rotatablysupports a plurality of planet gears 827 such that each planet gear 827simultaneously, and meshingly engages both the outer, ring gear member824 and the inner, sun gear member 822 of the planetary gear set 820.

The planetary gear set 830, also employs an outer gear member 834,typically designated as the ring gear. The ring gear member 834circumscribes an inner gear member 832, typically designated as the sungear. A carrier member 836 rotatably supports a plurality of planetgears 837 such that each planet gear 837 simultaneously, and meshinglyengages both the outer, ring gear member 834 and the inner, sun gearmember 832 of the planetary gear set 830.

The input shaft 17 is continuously connected to the ring gear member824. The output shaft 19 is continuously connected to the ring gearmember 834.

An interconnecting member 870 continuously connects the carrier member826 with the carrier member 836.

The preferred embodiment 810 also incorporates first, second and thirdmotor/generators 880, 882 and 884, respectively. The stator of the firstmotor/generator 880 is secured to the transmission housing 860. Therotor of the first motor/generator 880 is secured to the sun gear member822.

The stator of the second motor/generator 882 is secured to thetransmission housing 860. The rotor of the second motor/generator 882 issecured to the sun gear member 832.

The stator of the third motor/generator 884 is secured to thetransmission housing 860. The rotor of the third motor/generator 884 issecured to the carrier member 836.

The hybrid transmission 814 receives power from the engine 12, and alsoexchanges power with an electric power source 886, which is operablyconnected to a controller 888.

Description of a Tenth Exemplary Embodiment

With reference to FIG. 10, a powertrain 910 is shown, including anengine 12 connected to one preferred embodiment of the improvedelectrically variable transmission (EVT), designated generally by thenumeral 914. Transmission 914 is designed to receive at least a portionof its driving power from the engine 12. As shown, the engine 12 has anoutput shaft that serves as the input member 17 of the transmission 914.A transient torque damper (not shown) may also be implemented betweenthe engine 12 and the input member 17 of the transmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 914.An output member 19 of the transmission 914 is connected to a finaldrive 16.

The transmission 914 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 920 and 930. The planetary gear set920 employs an outer gear member 924, typically designated as the ringgear. The ring gear member 924 circumscribes an inner gear member 922,typically designated as the sun gear. A carrier member 926 rotatablysupports a plurality of planet gears 927, 928. Each planet gear 927meshingly engages sun gear member 922 and each planet gear 928 meshinglyengages the ring gear member 924 and the respective planet gear 927 ofthe planetary gear set 920.

The planetary gear set 930 employs an outer gear member 934, typicallydesignated as the ring gear. The ring gear member 934 circumscribes aninner gear member 932, typically designated as the sun gear. A carriermember 936 rotatably supports a plurality of planet gears 937 such thateach planet gear 937 simultaneously, and meshingly engages both theouter, ring gear member 934 and the inner, sun gear member 932 of theplanetary gear set 930.

The input shaft 17 is continuously connected to the ring gear member924. The output shaft 19 is continuously connected to the carrier member936.

An interconnecting member 970 continuously connects the carrier member926 with the sun gear member 932.

The preferred embodiment 910 also incorporates first, second and thirdmotor/generators 980, 982 and 984, respectively. The stator of the firstmotor/generator 980 is secured to the transmission housing 960. Therotor of the first motor/generator 980 is secured to the carrier member926.

The stator of the second motor/generator 982 is secured to thetransmission housing 960. The rotor of the second motor/generator 982 issecured to the sun gear member 922.

The stator of the third motor/generator 984 is secured to thetransmission housing 960. The rotor of the third motor/generator 984 issecured to the ring gear member 934.

The hybrid transmission 914 receives power from the engine 12, and alsoexchanges power with an electric power source 986, which is operablyconnected to a controller 988.

Description of an Eleventh Exemplary Embodiment

With reference to FIG. 11, a powertrain 1010 is shown, including anengine 12 connected to one preferred embodiment of the improvedelectrically variable transmission (EVT), designated generally by thenumeral 1014. Transmission 1014 is designed to receive at least aportion of its driving power from the engine 12. As shown, the engine 12has an output shaft that serves as the input member 17 of thetransmission 1014. A transient torque damper (not shown) may also beimplemented between the engine 12 and the input member 17 of thetransmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 1014.An output member 19 of the transmission 1014 is connected to a finaldrive 16.

The transmission 1014 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 1020 and 1030. The planetary gear set1020 employs an outer gear member 1024, typically designated as the ringgear. The ring gear member. 1024 circumscribes an inner gear member1022, typically designated as the sun gear. A carrier member 1026rotatably supports a plurality of planet gears 1027 such that eachplanet gear 1027 simultaneously, and meshingly engages both the outer,ring gear member 1024 and the inner, sun gear member 1022 of theplanetary gear set 1020.

The planetary gear set 1030 employs an outer gear member 1034, typicallydesignated as the ring gear. The ring gear member 1034 circumscribes aninner gear member 1032, typically designated as the sun gear. A carriermember 1036 rotatably supports a plurality of planet gears 1037 suchthat each planet gear 1037 simultaneously, and meshingly engages boththe outer, ring gear member 1034 and the inner, sun gear member 1032 ofthe planetary gear set 1030.

The input shaft 17 is continuously connected to the carrier member 1036.The output shaft 19 is continuously connected to the ring gear member1024.

An interconnecting member 1070 continuously connects the carrier member1026 with the ring gear member 1034.

The preferred embodiment 1010 also incorporates first, second and thirdmotor/generators 1080, 1082 and 1084, respectively. The stator of thefirst motor/generator 1080 is secured to the transmission housing 1060.The rotor of the first motor/generator 1080 is secured to the sun gearmember 1032.

The stator of the second motor/generator 1082 is secured to thetransmission housing 1060. The rotor of the second motor/generator 1082is secured to the ring gear member 1034.

The stator of the third motor/generator 1084 is secured to thetransmission housing 1060. The rotor of the third motor/generator 1084is secured to the sun gear member 1022.

The hybrid transmission 1014 receives power from the engine 12, and alsoexchanges power with an electric power source 1086, which is operablyconnected to a controller 1088.

Description of a Twelfth Exemplary Embodiment

With reference to FIG. 12, a powertrain 1110 is shown, including anengine 12 connected to one preferred embodiment of the improvedelectrically variable transmission (EVT), designated generally by thenumeral 1114. Transmission 1114 is designed to receive at least aportion of its driving power from the engine 12. As shown, the engine 12has an output shaft that serves as the input member 17 of thetransmission 1114. A transient torque damper (not shown) may also beimplemented between the engine 12 and the input member 17 of thetransmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 1114.An output member 19 of the transmission 1114 is connected to a finaldrive 16.

The transmission 1114 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 1120 and 1130. The planetary gear set1120 employs an outer gear member 1124, typically designated as the ringgear. The ring gear member 1124 circumscribes an inner gear member 1122,typically designated as the sun gear. A carrier member 1126 rotatablysupports a plurality of planet gears 1127 such that each planet gear1127 simultaneously, and meshingly engages both the outer, ring gearmember 1124 and the inner, sun gear member 1122 of the planetary gearset 1120.

The planetary gear set 1130 employs an outer gear member 1134, typicallydesignated as the ring gear. The ring gear member 1134 circumscribes aninner gear member 1132, typically designated as the sun gear. A carriermember 1136 rotatably supports a plurality of planet gears 1137 suchthat each planet gear 1137 simultaneously, and meshingly engages boththe outer, ring gear member 1134 and the inner, sun gear member 1132 ofthe planetary gear set 1130.

The input shaft 17 is continuously connected to the sun gear member1132. The output shaft 19 is continuously connected to the ring gearmember 1124.

An interconnecting member 1170 continuously connects the carrier member1126 with the ring gear member 1134.

The preferred embodiment 1110 also incorporates first, second and thirdmotor/generators 1180, 1182 and 1184, respectively. The stator of thefirst motor/generator 1180 is secured to the transmission housing 1160.The rotor of the first motor/generator 1180 is secured to the carriermember 1136.

The stator of the second motor/generator 1182 is secured to thetransmission housing 1160. The rotor of the second motor/generator 1182is secured to the ring gear member 1134.

The stator of the third motor/generator 1184 is secured to thetransmission housing 1160. The rotor of the third motor/generator 1184is secured to the sun gear member 1122.

The hybrid transmission 1114 receives power from the engine 12, and alsoexchanges power with an electric power source 1186, which is operablyconnected to a controller 1188.

Description of a Thirteenth Exemplary Embodiment

With reference to FIG. 13, a powertrain 1210 is shown, including anengine 12 connected to one preferred embodiment of the improvedelectrically variable transmission (EVT), designated generally by thenumeral 1214. Transmission 1214 is designed to receive at least aportion of its driving power from the engine 12. As shown, the engine 12has an output shaft that serves as the input member 17 of thetransmission 1214. A transient torque damper (not shown) may also beimplemented between the engine 12 and the input member 17 of thetransmission.

In the embodiment depicted the engine 12 may be a fossil fuel engine,such as a gasoline or diesel engine which is readily adapted to provideits available power output typically delivered at a selectable number ofrevolutions per minute (RPM).

Irrespective of the means by which the engine 12 is connected to thetransmission input member 17, the transmission input member 17 isoperatively connected to a planetary gear set in the transmission 1214.An output member 19 of the transmission 1214 is connected to a finaldrive 16.

The transmission 1214 utilizes two differential gear sets, preferably inthe nature of planetary gear sets 1220 and 1230. The planetary gear set1220 employs an outer gear member 1224, typically designated as the ringgear. The ring gear member 1224 circumscribes an inner gear member 1222,typically designated as the sun gear. A carrier member 1226 rotatablysupports a plurality of planet gears 1227 such that each planet gear1227 simultaneously, and meshingly engages both the outer, ring gearmember 1224 and the inner, sun gear member 1222 of the planetary gearset 1220.

The planetary gear set 1230 employs an outer gear member 1234, typicallydesignated as the ring gear. The ring gear member 1234 circumscribes aninner gear member 1232, typically designated as the sun gear. A carriermember 1236 rotatably supports a plurality of planet gears 1237 suchthat each planet gear 1237 simultaneously, and meshingly engages boththe outer, ring gear member 1234 and the inner, sun gear member 1232 ofthe planetary gear set 1230.

The input shaft 17 is continuously connected to the carrier member 1236.The output shaft 19 is continuously connected to the ring gear member1224.

An interconnecting member 1270 continuously connects the sun gear member1222 with the ring gear member 1234.

The preferred embodiment 1210 also incorporates first, second and thirdmotor/generators 1280, 1282 and 1284, respectively. The stator of thefirst motor/generator 1280 is secured to the transmission housing 1260.The rotor of the first motor/generator 1280 is secured to the sun gearmember 1232 via an offset drive 1290, such as a belt or chain, which maychange the speed ratio.

The stator of the second motor/generator 1282 is secured to thetransmission housing 1260. The rotor of the second motor/generator 1282is secured to the ring gear member 1234.

The stator of the third motor/generator 1284 is secured to thetransmission housing 1260. The rotor of the third motor/generator 1284is secured to the carrier member 1226 via an offset gear 1292.

The hybrid transmission 1214 receives power from the engine 12, and alsoexchanges power with an electric power source 1286, which is operablyconnected to a controller 1288.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

1. An electrically variable transmission comprising: an input member toreceive power from an engine; an output member, said transmission havingno more than one output member; first, second and thirdmotor/generators; first and second differential gear sets each havingfirst, second and third members; said input member being continuouslyconnected with a member of said gear sets, and said output member beingcontinuously connected with another member of said gear sets; aninterconnecting member continuously connecting said first member of saidfirst gear set with said first member of said second gear set, saidtransmission having no more than one interconnecting member between saidfirst gar set and said second gear set; said first motor/generator beingcontinuously connected with a member of said first gear set; said secondmotor/generator being continuously connected with a member of saidsecond gear set; said third motor/generator being continuously connectedwith a member of said first or second gear set; wherein none of saidfirst, second and third motor/generators are directly connected withsaid input member; wherein none of said first, second, and thirdmotor/generators are directly connected with said output member; andwherein said first, second and third motor/generators are operable toprovide an electrically variable transmission with a continuouslyvariable range of speed ratios between said input member and said outputmember.
 2. The electrically variable transmission of claim 1, whereinsaid first and second differential gear sets are planetary gear sets. 3.The electrically variable transmission of claim 2, wherein the first,second and third members of the respective first and second planetarygear sets include respective planet carrier assembly members; andwherein both of said respective planet carrier assembly members of saidplanetary gear sets are single-pinion carriers.
 4. The electricallyvariable transmission of claim 2, wherein the first, second and thirdmembers of the respective first and second planetary gear sets includerespective planet carrier assembly members; and wherein at least one ofsaid respective planet carrier assembly members of said planetary gearsets is a double-pinion carrier.
 5. The electrically variabletransmission of claim 1, wherein at least one of said motor/generatorsis connected with said gear sets through at least one fixed or variablespeed ratio device.
 6. The electrically variable transmission of claim1, wherein the electrically variable transmission is characterized bythe absence of clutches.
 7. The electrically variable transmission ofclaim 1, wherein at least one of said motor/generators is connected withsaid output member through at least one of said members of the first,second and third gear sets.
 8. An electrically variable transmissioncomprising: an input member to receive power from an engine; an outputmember, said transmission having no more than one output member, first,second and third motor/generators; first and second differential gearsets each having first, second and third members; said input memberbeing continuously connected with a member of said gear sets, and saidoutput member being continuously connected with another member of saidgear sets; an interconnecting member continuously connecting said firstmember of said first gear set with said first member of said second gearset, said transmission having no more than one interconnecting memberbetween said first gear set and said second gear set; said first, secondand third motor/generators being continuously connected with members ofsaid gear sets; wherein none of said first, second and thirdmotor/generators are directly connected with said input member; whereinnone of said first, second, and third motor/generators are directlyconnected with said output member; and wherein said first, second andthird motor/generators are operable to provide an electrically variabletransmission with a continuously variable range of speed ratios betweensaid input member and said output member.
 9. The electrically variabletransmission of claim 8, wherein said first and second differential gearsets are planetary gear sets.
 10. The electrically variable transmissionof claim 9, wherein the first, second and third members of therespective first and second differential gear sets include respectiveplanet carrier assembly members; and wherein both of said respectiveplanet carrier assembly members of said planetary gear sets aresingle-pinion carriers.
 11. The electrically variable transmission ofclaim 9, wherein the first, second and third members of the respectivefirst and second differential gear sets include respective planetcarrier assembly members; and wherein at least one of said respectiveplanet carrier assembly members of said planetary gear sets is adouble-pinion carrier.
 12. The electrically variable transmission ofclaim 8, wherein at least one of said motor/generators is connected withsaid gear sets through at least one fixed or variable speed rationdevice.
 13. The electrically variable transmission of claim 8, whereinsaid input member and at least one of said motor/generators areconnected with said first differential gear set.
 14. The electricallyvariable transmission of claim 8, wherein said input member and at leasttwo of said motor/generators are connected with said first differentialgear set.
 15. The electrically variable transmission of claim 8, whereinone of said input member and said output member is connected with saidinterconnecting member.
 16. The electrically variable transmission ofclaim 8, wherein said input member and said output member are eachconnected with different respective members of one of said differentialgear sets.
 17. The electrically variable transmission of claim 8,wherein said input member is connected with a member of said firstdifferential gear set and said output member is connected with a memberof said second differential gear set.
 18. The electrically variabletransmission of claim 8, wherein none of said members of said gear setsare connected to a stator of one of said motor/generators.
 19. Theelectrically variable transmission of claim 8, wherein none of saidmembers of said gear sets are connected to a stationary member.